[Washington Post] It has been widely discussed — but not yet peer reviewed. Now, though, you can at least read it for yourself and see what you think.

A lengthy, ambitious, and already contested paper by longtime NASA climate scientist James Hansen and 16 colleagues appeared online Thursday in Atmospheric Chemistry and Physics Discussion, an open-access journal published by the European Geosciences Union…

The study raises the possibility of a more rapid rate of sea level rise in this century than forecast by the U.N.’s Intergovernmental Panel on Climate Change, whose research is widely regarded as the gold standard of climate research — but also often criticized for being too conservative.

Moreover, the study postulates that this faster sea level rise, brought on by the melting of parts of Antarctica and Greenland, could lead to a number of climate change “feedbacks” that could shut down the oceans’ circulation; stratify the polar seas with warmer waters trapped below cold surface layers; increase the temperature difference between low and high latitudes; and generate stronger storms…

[Dot Earth] The paper got attention in advance because of this passage and, particularly, the five highlighted words (my emphasis):

We conclude that continued high emissions will make multi-meter sea level rise practically unavoidable andlikely to occur this century. Social disruption and economic consequences of such large sea level rise could be devastating. It is not difficult to imagine that conflicts arising from forced migrations and economic collapse might make the planet ungovernable, threatening the fabric of civilization. This image of our planet with accelerating meltwater includes growing climate chaos and storminess, as meltwater causes cooling around Antarctica and in the North Atlantic while the tropics and subtropics continue to warm. Rising seas and more powerful storms together are especially threatening, providing strong incentive to phase down CO2 emissions rapidly.

The extent of danger posed by sea-level rise is a function of thepaceof change far more than the final number. If there is new clarity on near-term coastal retreats, that is the news.